隨著量子運算的快速發展，傳統公鑰加密系統（如 RSA）面臨嚴重的安全威脅。為了應對此挑戰，美國國家標準暨技術研究院（NIST）發佈了 FIPS 205 標準，制定了「無狀態雜湊數位簽章演算法」（SLH-DSA）。本論文旨在對 SLH-DSA 的結構與設計進行系統性的組件分析。
首先，我們詳細探討 SLH-DSA 的核心組成部分，包括幾次性簽章（FORS）、一次性簽章（WOTS+）以及超樹（Hypertree）結構，並解釋這些組件如何協作以達成無狀態簽章的特性。接著，我們整理了實務部署中可能出現的安全性問題。例如一次性簽章 WOTS+ 結構在遭遇「故障注入攻擊」（Fault Injection）時的弱點，除了[Gen23]提供的快取策略外，我們也引進了[LP19]「雜湊糾纏」（Hash En-tanglement）的方法探討其防禦錯誤攻擊的可行性。針對旁通道的硬體攻擊，我們引用了[Flu24]的私鑰生成樹手法進行討論。最後，針對資源受限的物聯網設備，[MC25]透過調整雜湊函數輸入順序來減少記憶體讀取次數的硬體優化策略。
總體而言，本文視覺化的拆解說明FIPS-205之簽章結構，並且彙整了針對該簽章方法提出的安全性與效率考量之優化策略。

With the rapid growth of quantum computing, traditional public-key cryptosystems like RSA face serious security risks. To solve this problem, NIST published the FIPS-205 standard, which defines the Stateless Hash-Based Digital Signature Algorithm (SLH-DSA). This paper provides a systematic analysis of the structure and design of SLH-DSA.
First, we examine the main components of SLH-DSA, including Few-Time Signatures (FORS), One-Time Signatures (WOTS+), and the Hypertree structure. We explain how these parts work together to achieve the "stateless" property. Second, we summarize potential security issues in real-world use. For example, we discuss the vulnerability of WOTS+ to fault injection attacks. In addition to the caching strategies found in [Gen23], we introduce the "Hash Entanglement" method from [LP19] to explore its feasibility for defending against such attacks. For hardware-level side-channel attacks, we discuss a key generation tree approach based on [Flu24]. Finally, for resource-constrained IoT devices, this paper includes an analysis of hardware optimiza-tion strategies, reordering hash function inputs to reduce memory access times by [MC25].
In summary, this paper revisits the signing structure of FIPS-205 and organizes the security and efficiency optimization strategies for this scheme.

[BHK+19] Daniel J. Bernstein, Andreas Hülsing, Stefan Kölbl, Ruben Niederhagen, Joost Rijneveld, and Peter Schwabe. The sphincs+ signature framework. In Proceed-ings of the 2019 ACM SIGSAC Conference on Computer and Communications Security, CCS ’19, page 2129–2146. Association for Computing Machinery, 2019.
[Flu24] Scott Fluhrer. Side channel resistant sphincs+. Cryptology ePrint Archive, Paper 2024/500, 2024.
[Gen23] Aymeric Genêt. On protecting SPHINCS+ against fault attacks. Cryptology ePrint Archive, Paper 2023/042, 2023.
[GMR24] Laurie E. Locascio Gina M. Raimondo. Stateless hash-based digital signature standard (slh-dsa). Technical Report FIPS 205, National Institute of Standards and Technology (NIST), 2024.
[LP19] Luis A. Lizama-Perez. Digital signatures over hash-entangled chains. In Springer Nature Switzerland AG 2019, 2019.
[MC25] Alexander Magyari and Yuhua Chen. Optimizing sphincs+ for low-power devices. Electronics, 2025.
[Nat24] National Institute of Standards and Technology. FIPS 204: Module-Lattice-Based Digital Signature Standard. Technical report, U.S. Department of Commerce, August 2024.
[PP10] Christof Paar and Jan Pelzl. Understanding Cryptography: A Textbook for Stu-dents and Practitioners. Springer, 2010.